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杨树是北半球中纬度平原地区广为栽培的树种。目前我国栽培的杨树,多起源于纬度较高的地方,在纬度较低的暖温带和亚热带的平原地区,尚缺少速生优质和抗病的良种资源。 自十九世纪以来,杨树引种栽培广泛开展,尤以本世纪五十年代后,意大利选出了几个南方型美洲黑杨栽培无性系,引起了人们对美洲黑杨这个种和它的栽培无性系的高度重视。除在地中海各国广泛引种外,已逐渐推向南半球和低纬度地区。 1972年我们第一次引种了亲本起源于较低纬度的Ⅰ—63和Ⅰ—69等美洲黑杨栽培无性系,经过几年的多点栽培试验初步证明,适宜于南方栽培,这就为我国杨树栽培向南推移展现了广阔的前景。
Poplar is a widely cultivated tree species in the mid-latitude plains of the northern hemisphere. At present, poplar cultivated in our country mostly originated from areas with relatively high latitudes. In the warm latitudes and subtropics plains of low latitudes, there are still no provenances of good quality and disease resistant. Since the 19th century, introduction and cultivation of poplar have been carried out extensively. Especially after the fifties of this century, several southern poplar cultivation clones in Italy were selected by Italy, causing people to poplar this species and its cultivation Clones attach great importance. In addition to the widespread introduction of the Mediterranean countries, has gradually pushed the southern hemisphere and low latitudes. In 1972, we first introduced the clonal origins of I-63 and I-69, which originated from lower latitudes. After several years of multi-point cultivation experiments, it was initially proved that it is suitable for cultivation in the South, Poplar cultivation southward to show a broad prospect.